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Commit 9470e24f authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
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ipv6: sctp: clone options to avoid use after free 



SCTP is lacking proper np->opt cloning at accept() time.

TCP and DCCP use ipv6_dup_options() helper, do the same
in SCTP.

We might later factorize this code in a common helper to avoid
future mistakes.

Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarVlad Yasevich <vyasevich@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d188ba86

net/sctp/ipv6.c

+8 −0
Original line number Diff line number Diff line
@@ -641,6 +641,7 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk, 
	struct sock *newsk;

	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);

	struct sctp6_sock *newsctp6sk;

	struct ipv6_txoptions *opt;



	newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, 0);

	if (!newsk)
@@ -660,6 +661,13 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk, 


	memcpy(newnp, np, sizeof(struct ipv6_pinfo));



	rcu_read_lock();

	opt = rcu_dereference(np->opt);

	if (opt)

		opt = ipv6_dup_options(newsk, opt);

	RCU_INIT_POINTER(newnp->opt, opt);

	rcu_read_unlock();



	/* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()

	 * and getpeername().

	 */